Pillows and cushions are generally formed by encasing some form of filling within a sealed envelope. The filling can take many forms from non-resilient cotton waste to resilient foam rubber and a wide variety of other materials. In most cases, the envelope is formed from a cloth or similar material, and very often, a covering such as a pillow case or cushion cover is used over the cushion or pillow. These covers are also normally formed from a cloth and usually serve the dual role of being decorative and permitting laundering without the need to launder the encased pillow or cushion.
When pillows and cushions are used as a support for the head of a person, the face comes in very close contact with the outer surface. Consequently, the user breathes the air surrounding the pillow. Both the outer covering of the pillow or cushion and the pillow or cushion itself, are susceptible to contamination by saliva, perspiration and other bodily fluids of previous users. This can lead to offensive odors being inhaled by subsequent users, and in some cases, the risk of inhalation or contact with germs or viruses. Whilst the practice of changing pillow cases or cushion covers does to some extent avoid this problem, it does not adequately deal with the problem of contamination of the pillow cushion itself.